Unable to accept challenge invitation

[Dredgenaut]

I have a Fitbit Alta and I'm using the app with an android phone.  I received an email that a friend of a friend wanted to invite me to a challenge but when I clicked the included link it only took me to a blank page.  I also checked the app and the last two workweek hustle challenges are still there with no way to exit them.  I also can't find the challenge that I received the email notification for.  Please help!

Moderator Edit: Updated Subject For Clarity.

[RobertoME]

Hi there @Dredgenaut, let me give you a warm welcome to the Fitbit Community. 

I'm wondering if the two challenges you have mentioned have finished already? Is not that will affect to accept the invitation, is just out of curiosity. In case you want to exit them go to your active challenge and in the right upper corner you'll see three dots in line > Tap here and select "Options" > Once you access here, select the exit challenge option.

About the invitation, try to update your app to the newest version for android, which is 2.49.

Once you have updated the app, Log out from your Fitbit app and go to your phone settings. Acces to the App manager option and look for the Fitbit app in your downloaded apps list. Clear the app cache and data and finish this workaround by restarting your phone. When your phone has initialized again, go back to your app and see if you have the invitation available. Otherwise try to request the invitation again after the workaround.

Let me know how it goes. Don't forget to keep me posted if the issue persists.